The present invention relates to a semiconductor device that includes a semiconductor element for high frequency applications and an overcurrent-protecting function in a hollow airtight package and a method of manufacturing the same.
An example of the semiconductor device employing the hollow package in the conventional art is shown in FIG. 9. This electronic parts comprise a base substrate 1 formed of ceramic, etc., a lead 2 for external connection, and a cap 3 formed similarly of ceramic. A semiconductor chip 5 is adhered onto a surface of an element mounting portion 4 of the lead 2, then the semiconductor chip 5 and the lead 2 are connected via bonding wires 6, and then the semiconductor chip 5 is sealed in an airtight space 7 constructed by the cap 3 (for example, Patent Application Publication Hei 10-173117).
Such parts are manufactured via steps of preparing the lead 2 in the form of a lead frame, then bonding the semiconductor chip 5 to the lead frame via die bonding or wire bonding, then mounting the base substrate 1 on a bottom surface of the lead frame, then mounting the cap 3 on the base substrate 1 to put the leads 2 between them, and then cutting/shaping the leads 2.
However, in the semiconductor device in the conventional art, there is the subject that, since the base substrate 1 and the cap 3 are mounted on the lead frame every element, the manufacturing steps become complicated and are not suited for the mass production.
Also, there is the problem that, since the semiconductor chip 5 is sealed in the airtight space 7 that is constructed by the cap 3 made of ceramic, etc., the adhesion state cannot be checked by the visual inspection and thus it is difficult to remove the semiconductor device in which the adhesion failure is caused.
In addition, there is the problem that, since the above semiconductor device has the structure to project the lead 2 from the base substrate 1, a packaging area is large when such semiconductor device is packaged onto the printed circuit board.
Further, in the recent electronic devices such as the mobile telephone, etc. that have the portability and are driven by the rechargeable battery, measure must be taken to improve the reverse connection of the power supply in the charging operation. In such case, an overcurrent protection element is indispensable. But, in the conventional art, there is no overcurrent protection element that meets the light weight and the small size. Thus, there is the drawback that the increase in size of the electronic device is brought about.